fix timer_name check in rtp

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@9472 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/switch_rtp.c

@@ -798,7 +798,7 @@ SWITCH_DECLARE(switch_status_t) switch_rtp_create(switch_rtp_t **new_rtp_session
 	rtp_session->ms_per_packet = ms_per_packet;
 	rtp_session->samples_per_interval = rtp_session->conf_samples_per_interval = samples_per_interval;
 
-	if (!strcasecmp(timer_name, "none")) {
+	if (timer_name && !strcasecmp(timer_name, "none")) {
 		timer_name = NULL;
 	}